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Merge pull request 'Port optimized path traversal algorithm from Antimony' (#168) from optimize-path-traversal into next

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Reviewed-on: https://codeberg.org/srb2classic/srb2classic/pulls/168
This commit is contained in:
Gustaf Alhäll 2025-10-20 20:11:53 +02:00 committed by NepDisk
parent aeedd2fd10
commit 4801c68755
2 changed files with 35 additions and 52 deletions
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2
src/p_local.h
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@ -44,7 +44,7 @@ extern consvar_t cv_naturalcamera;
// against lines and things
#define MAPBLOCKUNITS 128
#define MAPBLOCKSIZE (MAPBLOCKUNITS*FRACUNIT)
#define MAPBLOCKSHIFT (FRACBITS+7)
#define MAPBLOCKSHIFT (FRACBITS+8)
#define MAPBMASK (MAPBLOCKSIZE-1)
#define MAPBTOFRAC (MAPBLOCKSHIFT-FRACBITS)

85
src/p_maputl.c
View file

@ -1741,12 +1741,6 @@ boolean P_PathTraverse(fixed_t px1, fixed_t py1, fixed_t px2, fixed_t py2,
validcount++;
intercept_p = intercepts;
if (((px1 - bmaporgx) & (MAPBLOCKSIZE-1)) == 0)
px1 += FRACUNIT; // Don't side exactly on a line.
if (((py1 - bmaporgy) & (MAPBLOCKSIZE-1)) == 0)
py1 += FRACUNIT; // Don't side exactly on a line.
g_trace.x = px1;
g_trace.y = py1;
g_trace.dx = px2 - px1;
@ -1760,17 +1754,8 @@ boolean P_PathTraverse(fixed_t px1, fixed_t py1, fixed_t px2, fixed_t py2,
// blockmap traversal algorithm ported from antimony
int gridpos_x = (unsigned)px1 >> MAPBLOCKSHIFT;
int gridpos_y = (unsigned)py1 >> MAPBLOCKSHIFT;
if (flags & PT_ADDLINES)
if (!P_BlockLinesIterator(gridpos_x, gridpos_y, PIT_AddLineIntercepts))
return false; // early out
if (flags & PT_ADDTHINGS)
if (!P_BlockThingsIterator(gridpos_x, gridpos_y, PIT_AddThingIntercepts))
return false; // early out
int endpos_x = (unsigned)px2 >> MAPBLOCKSHIFT;
int endpos_y = (unsigned)py2 >> MAPBLOCKSHIFT;
if (gridpos_x == endpos_x && gridpos_y == endpos_y)
return P_TraverseIntercepts(trav, FRACUNIT);
fixed_t pos_x = px1;
fixed_t pos_y = py1;
@ -1778,54 +1763,61 @@ boolean P_PathTraverse(fixed_t px1, fixed_t py1, fixed_t px2, fixed_t py2,
fixed_t dist_y = py2 - py1;
int dir_x = dist_x < 0 ? -1 : 1;
int dir_y = dist_y < 0 ? -1 : 1;
fixed_t step = 1 << MAPBLOCKSHIFT;
fixed_t delta_x;
fixed_t delta_y;
// special cases for 0 to avoid crashes
if (dist_y == 0)
{
delta_x = INT32_MAX;
delta_x = FRACUNIT;
delta_y = 0;
}
else if (dist_x == 0)
{
delta_x = 0;
delta_y = INT32_MAX;
delta_y = FRACUNIT;
}
else
{
delta_x = FixedDiv2(dist_x, abs(dist_y));
delta_y = FixedDiv2(dist_y, abs(dist_x));
delta_x = abs(FixedDiv2(FRACUNIT, dist_x));
delta_y = abs(FixedDiv2(FRACUNIT, dist_y));
}
fixed_t hitx_x;
if (dir_x > 0)
hitx_x = ((gridpos_x+1) << MAPBLOCKSHIFT) - pos_x;
else
hitx_x = pos_x - (gridpos_x << MAPBLOCKSHIFT);
fixed_t hity_y;
if (dir_y > 0)
hity_y = ((gridpos_y+1) << MAPBLOCKSHIFT) - pos_y;
else
hity_y = pos_y - (gridpos_y << MAPBLOCKSHIFT);
while (gridpos_x >= 0 && gridpos_y >= 0 && gridpos_x < bmapwidth && gridpos_y < bmapheight)
{
fixed_t hitx_x;
if (dir_x > 0)
hitx_x = (gridpos_x+1) << MAPBLOCKSHIFT;
else
hitx_x = gridpos_x << MAPBLOCKSHIFT;
if (flags & PT_ADDLINES)
if (!P_BlockLinesIterator(gridpos_x, gridpos_y, PIT_AddLineIntercepts))
return false; // early out
if (flags & PT_ADDTHINGS)
if (!P_BlockThingsIterator(gridpos_x, gridpos_y, PIT_AddThingIntercepts))
return false; // early out
if (gridpos_x == endpos_x && gridpos_y == endpos_y)
break;
fixed_t hity_y;
if (dir_y > 0)
hity_y = (gridpos_y+1) << MAPBLOCKSHIFT;
else
hity_y = gridpos_y << MAPBLOCKSHIFT;
hitx_x -= pos_x;
hity_y -= pos_y;
fixed_t hitx_y = FixedMul(delta_y, abs(hitx_x));
fixed_t hity_x = FixedMul(delta_x, abs(hity_y));
if (FixedMul(hitx_x, hitx_x) + FixedMul(hitx_y, hitx_y) > FixedMul(hity_x, hity_x) + FixedMul(hity_y, hity_y))
fixed_t hitx_y = FixedMul(delta_x, hitx_x);
fixed_t hity_x = FixedMul(delta_y, hity_y);
if (hitx_y > hity_x)
{
gridpos_y += dir_y;
pos_x += hity_x;
pos_y += hity_y;
hity_y += step;
}
else if (FixedMul(hitx_x, hitx_x) + FixedMul(hitx_y, hitx_y) < FixedMul(hity_x, hity_x) + FixedMul(hity_y, hity_y))
else if (hitx_y < hity_x)
{
gridpos_x += dir_x;
pos_x += hitx_x;
pos_y += hitx_y;
hitx_x += step;
}
else
{
@ -1844,18 +1836,9 @@ boolean P_PathTraverse(fixed_t px1, fixed_t py1, fixed_t px2, fixed_t py2,
gridpos_y += dir_y;
}
pos_x += hitx_x;
pos_y += hitx_y;
hitx_x += step;
hity_y += step;
}
if (flags & PT_ADDLINES)
if (!P_BlockLinesIterator(gridpos_x, gridpos_y, PIT_AddLineIntercepts))
return false; // early out
if (flags & PT_ADDTHINGS)
if (!P_BlockThingsIterator(gridpos_x, gridpos_y, PIT_AddThingIntercepts))
return false; // early out
if (gridpos_x == endpos_x && gridpos_y == endpos_y)
break;
}
// Go through the sorted list